This invention relates to optical scanning systems, and more particularly to techniques for providing multiple resolutions.
Moving mirror scanning systems are known, wherein two mirrors are moved relative to a target to be scanned to direct a reflected beam to a sensor. It would be advantageous to provide a technique for changing the resolution of the system without requiring a separate motor for changing lenses.
In accordance with an aspect of the invention, a scanner system is described, wherein two lenses are mounted on a slider positioned in the optical light path between two moving mirrors and the optical sensor. Each mirror is mounted on a moving carriage. The slider is bistable in two alignment positions, one for each lens. The slider is moved by the motion of one of the carriages. As the carriage moves toward the lens slider, a linkage causes the slider to move from the position it is currently in to the other position. This system allows the slider to be shuttled from one position to the other, thereby changing resolutions, using energy provided by the same motor that moves the mirrors.
In accordance with another aspect, methods are described for changing imaging resolution in an optical scanning system having a fixed optical sensor, and a moving carriage. An exemplary method includes:
moving the carriage to a position outside a normal scanning area;
engaging a slider linkage coupled to a slider structure which is movable between a plurality of home positions, the slider structure having mounted thereon a plurality of lenses of different optical power, wherein each said home position positions a corresponding one of said lenses in an optical scanning path for the system;
moving the slider structure to a home position by a driving force provided by motion of the carriage and the slider linkage; and
disengaging the carriage from the slider linkage.